CN115397116A - Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding - Google Patents

Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding Download PDF

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Publication number
CN115397116A
CN115397116A CN202210918965.3A CN202210918965A CN115397116A CN 115397116 A CN115397116 A CN 115397116A CN 202210918965 A CN202210918965 A CN 202210918965A CN 115397116 A CN115397116 A CN 115397116A
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China
Prior art keywords
circuit board
film
outer layer
layer circuit
upper bottom
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CN202210918965.3A
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Chinese (zh)
Inventor
李建根
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Huizhou Weide Circuit Co ltd
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Huizhou Weide Circuit Co ltd
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Priority to CN202210918965.3A priority Critical patent/CN115397116A/en
Publication of CN115397116A publication Critical patent/CN115397116A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/022—Processes for manufacturing precursors of printed circuits, i.e. copper-clad substrates
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding
    • H05K3/06—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding the conductive material being removed chemically or electrolytically, e.g. by photo-etch process
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
    • H05K3/18—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material
    • H05K3/188—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material by direct electroplating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/46—Manufacturing multilayer circuits

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing Of Printed Wiring (AREA)

Abstract

The invention provides a method for manufacturing a thick copper circuit board without a suspended edge, which comprises an outer layer circuit board; the upper bottom surface of the outer layer circuit board needs to be processed by electronickelling and electrogilding; the lower bottom surface of the outer layer circuit board does not need to be subjected to electro-nickel and electro-gold treatment; the manufacturing method of the outer layer circuit board comprises the following steps: firstly, the circuit on the upper bottom surface of the outer layer circuit board is manufactured, then the electric nickel and electric gold processing treatment is carried out on the electric nickel and electric gold area on the upper bottom surface of the outer layer circuit board, and then the circuit on the lower bottom surface of the outer layer circuit board is manufactured. The invention effectively overcomes the defects of the traditional nickel and gold electroplating process of the circuit board, so that the copper thickness of the thick copper circuit board cannot be reduced in the production process, the problem of suspended nickel and gold metal edges cannot be generated, the quality of the circuit board is improved, and the signal transmission stability and the product performance of the assembled circuit board are ensured.

Description

Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding
Technical Field
The invention belongs to the technical field of circuit board production and manufacturing, and particularly relates to a method for manufacturing a thick copper circuit board without a suspended edge for electro-nickel and electro-gold.
Background
The process of nickel and gold electroplating is one of very common surface treatment processes in the production process of circuit boards, and the process can be generally divided into the following two types of gold electroplating according to specific functions: the method specifically comprises the following steps: class 1: the electro-thin gold (0.3-3 micro inches) is commonly called electro 'water gold' due to the thickness of the gold, and is mainly used for welding; class 2: electro-thick gold (4-80 micro-inches), which is mainly used for non-soldering, such as for plug and pull electrical interconnection; compared with other surface treatments, the electro-thick gold has the advantages that: the surface is smooth, the service life is long, the electric thick gold contains cobalt element, the electric thick gold is mainly used for electric interconnection at non-welding positions, and has good insertion resistance, pull-out resistance and abrasion resistance, reliable connection performance, small contact resistance, wear resistance, corrosion resistance of various environments without connection faults and other excellent performances. Because the processes of the nickel electroplating and the gold electroplating are resistant to acid and alkali corrosion, the circuit boards of the nickel electroplating and the gold electroplating are generally made of positive films, after the circuit boards are electroplated with nickel and gold, the circuit patterns are directly etched by utilizing the acid and alkali corrosion resistance and the corrosion resistance of the nickel and the gold, and the liquid medicine only corrodes copper and the nickel and the gold are still left because the nickel and the gold have the corrosion resistance in the etching process.
However, in the actual production process, the corrosion of the liquid medicine to copper in the circuit board etching process not only occurs longitudinally, but also occurs transversely, so that the process can lead the electrified nickel and gold wires or PADs to generate suspended nickel and gold metal edges; meanwhile, in the actual production process, the fact that the metal edge of the circuit bottom copper is larger as the thickness of the circuit bottom copper is thicker is found, the bottom of the etched wire is in a suspended state, the process is generally suitable for a PCB with surface copper below 40 mu m and thin copper, when the thickness of the bottom copper is too thick, if the thickness of the copper is more than 70 mu m or 70 mu m, the traditional one-time board electro-thick copper is adopted to carry out negative film etching, the suspended nickel and metal edge generated after etching by the copper thickness increasing method is larger, the suspended nickel metal edge is larger, and the suspended nickel metal edge can be broken and flapped but part of the nickel metal edge can not be completely broken under the action of external pressure of post procedures such as a grinding brush, a screen printer and the like, so that the circuit board has poor appearance and electrical performance, and if the broken suspended nickel metal edge is thrown between two adjacent conductors, two adjacent conductors can generate poor short circuit, thereby causing scrapping, and a plurality of other poor hidden troubles exist.
In order to improve the above-mentioned problems of thick copper plates (copper thickness is 70um or more than 70 um) in the production process, the following methods are generally adopted in the prior art industry:
firstly, a microetching copper-reducing method is adopted: the method comprises the steps of carrying out micro-etching to reduce copper preferentially according to the copper thickness of the key positions or the PAD positions of the electro-nickel and the electro-gold, reducing the copper of the positions to 5-15UM, and then carrying out electro-nickel-gold, wherein the defects can be improved; but it does not meet the customer's requirement that the original copper thickness be 70um or more than 70 um;
secondly, adopting a method for separately etching and reducing copper: the copper thickness is etched and thinned to 5-15um, and then the electro-nickel gold is carried out, although the method effectively reduces the poor suspended edge; but it also does not meet the customer's requirement that the original copper thickness be 70um or above 70 um;
the two thick copper plate copper reduction methods obviously have the following disadvantages: for example, the original copper thickness of a client requires 2OZ (70 um or copper with thickness more than 70 um), the copper thickness of a key position is reduced to 5-15um according to the prior art, the copper thickness of the key position is obviously 55-65um lower than that of other positions, a slightly etched or etched part and a normal part can form a concave state, the key is obviously not in contact with the normal part in a plugging and unplugging manner, the copper thickness also affects the transmission of a product signal, and thus the product performance is greatly reduced. Based on the defects of the prior art and the limitations of the process, a thick copper circuit board which not only meets the requirements of the copper thickness of the circuit and the copper thickness of 2OZ or more (namely, the thick copper of 70um or more than 70 um) according to key positions, but also meets the requirements of the process of electronickelling and electrogilding on a circuit board and does not generate the problem of suspended nickel and gold metal edges is developed, and the circuit board production process of electronickelling and electrogilding without suspended edges becomes the urgent requirement of circuit board production enterprises.
Disclosure of Invention
The invention provides a method for manufacturing a thick copper circuit board without a suspended edge, which has strong practicability and wide application range, effectively overcomes the defects of the traditional process for electrically plating nickel and gold on the circuit board, particularly the defects of a thick copper plate (2 OZ or more), does not reduce the copper thickness of the thick copper circuit board in the production process, does not generate the problem of the suspended metal edge of nickel and gold, improves the quality of the circuit board, and ensures the stability of signal transmission of the assembled circuit board and the performance of a product.
The invention provides a method for manufacturing a thick copper circuit board without a suspended edge, which comprises an outer layer circuit board, a lower layer circuit board and a circuit board, wherein the circuit board is required to be manufactured on the upper bottom surface and the lower bottom surface of the circuit board; the upper bottom surface of the outer layer circuit board needs to be processed by electronickelling and electrogilding; the lower bottom surface of the outer layer circuit board does not need to be subjected to electro-nickel and electro-gold treatment; the manufacturing method of the outer layer circuit board comprises the following steps: firstly, the circuit on the upper bottom surface of the outer layer circuit board is manufactured, then the electric nickel and electric gold processing treatment is carried out on the electric nickel and electric gold area on the upper bottom surface of the outer layer circuit board, and then the circuit on the lower bottom surface of the outer layer circuit board is manufactured.
As a further improvement of the invention, the manufacturing method of the thick copper circuit board comprises the following specific steps:
s1, drilling, removing glue residues, depositing copper in holes and electroplating the whole board on an outer layer circuit board;
s2, firstly, carrying out surface treatment on the outer layer circuit board, pasting a dry film, manufacturing a negative film isolation circuit film, aligning, exposing, developing, acid etching, film stripping and cleaning, and carrying out optical detection on the circuit on the upper bottom surface of the outer layer circuit board;
s3, carrying out surface treatment, film pasting, positive film barrier circuit film manufacturing, alignment, exposure, development, electronickelling, electrogilding, film stripping and cleaning on the outer-layer circuit board;
s4, pasting a film on the outer layer circuit board, manufacturing a negative film for isolating a circuit film, aligning, exposing, developing, acid etching, removing the film, cleaning and optically detecting the circuit on the lower bottom surface of the outer layer circuit board;
s5, carrying out solder mask oil silk-screen printing, character printing and other surface treatment of non-electric gold positions on the outer layer circuit board;
and S6, forming and processing the outer-layer circuit board, and testing the electrical property function to obtain the circuit board.
As a further improvement of the present invention, the specific steps of step S2 are as follows:
s21, firstly, carrying out surface treatment on the outer-layer circuit board, and then pasting a layer of dry film on the upper bottom surface and the lower bottom surface of the outer-layer circuit board;
s22, manufacturing a first upper bottom surface negative film isolation circuit film corresponding to an upper bottom surface circuit pattern of the outer layer circuit board by adopting the negative film isolation circuit film; a first windowing area is arranged on the first upper bottom surface negative film blocking circuit film; the position of the first windowing area corresponds to the positions of an upper bottom surface circuit area of the outer layer circuit board and an area needing to be subjected to electro-nickel and electro-gold area treatment; manufacturing a first lower bottom surface negative film isolation circuit film corresponding to the lower bottom surface of the outer layer circuit board by adopting a full-page windowed negative film isolation circuit film;
s23, aligning and exposing the upper bottom surface dry film of the outer layer circuit board by adopting a first upper bottom surface negative film blocking circuit film, and aligning and exposing the lower bottom surface dry film of the outer layer circuit board by adopting a first lower bottom surface negative film blocking circuit film; then carrying out development and acid etching to manufacture a circuit on the upper bottom surface of the outer layer circuit board and an area needing electronickness and electrogilding;
s24, removing the film of the outer-layer circuit board by using an alkaline film removing liquid, and then cleaning the outer-layer circuit board;
and S25, carrying out optical detection on the circuit on the upper bottom surface of the outer layer circuit board.
As a further improvement of the present invention, the specific steps of step S3 are as follows:
s31, firstly, carrying out surface treatment on the outer-layer circuit board, and then pasting a layer of dry film on the upper bottom surface and the lower bottom surface of the outer-layer circuit board;
s32, manufacturing an upper bottom surface positive barrier circuit film corresponding to the upper bottom surface of the outer layer circuit board by adopting the positive barrier circuit film; the film of the upper bottom surface positive barrier circuit is provided with a positive barrier circuit film windowing area; the position of the positive film blocking circuit film windowing area corresponds to the position of an area, needing to be processed by the nickel and gold areas, on the upper bottom surface of the outer layer circuit board; adopting a positive solder resist film with a full-page window to manufacture a lower bottom surface positive barrier circuit film corresponding to the lower bottom surface of the outer layer circuit board;
s33, firstly, exposing the upper bottom surface dry film of the outer layer circuit board by adopting an upper bottom surface positive film to block the circuit film, and then exposing the lower bottom surface dry film of the outer layer circuit board by adopting a lower bottom surface positive film to block the circuit film; then carrying out development;
s34, after development, carrying out electric nickel and electric gold treatment on the outer layer circuit board, firstly electroplating a nickel layer in the electric nickel and electric gold area on the upper bottom surface of the outer layer circuit board, then carrying out electric gold treatment on the outer layer circuit board, and electroplating a gold layer on the nickel layer on the upper bottom surface of the outer layer circuit board;
s35, removing the film of the outer circuit board by adopting an alkaline film removing liquid, and then cleaning the outer circuit board.
As a further improvement of the present invention, the specific steps of step S4 are as follows:
s41, attaching a layer of dry film to the upper bottom surface and the lower bottom surface of the outer layer circuit board;
s42, manufacturing a second lower bottom surface negative film isolation circuit film corresponding to the lower bottom surface circuit diagram of the outer layer circuit board by adopting the negative film isolation circuit film; a second windowing area is arranged on the second lower bottom negative film blocking line film; the second lower windowing region corresponds to the lower bottom surface circuit region of the outer layer circuit board; a second upper bottom surface negative resistance welding film corresponding to the upper bottom surface of the outer layer circuit board is manufactured by adopting a full-page windowed negative resistance welding film;
s43, exposing the lower bottom surface dry film of the outer layer circuit board by adopting a second lower bottom surface negative film blocking circuit film, and then exposing the outer layer upper bottom surface dry film by adopting a second upper bottom surface negative film blocking circuit film; then carrying out development and acid etching to manufacture a circuit on the lower bottom surface of the outer layer circuit board;
s244, removing the outer layer circuit board by using an alkaline film removing liquid, and then cleaning the outer layer circuit board;
s45, carrying out optical detection on the circuit on the lower bottom surface of the outer-layer circuit board.
As a further improvement of the invention, in step S1, after the outer-layer circuit board is processed by copper deposition in the hole and full-board electroplating, a copper layer is electroplated on both the surface and the hole wall of the outer-layer circuit board, and the thickness of the copper layer on the surface of the outer-layer circuit board is more than 70 um; the copper thickness of the hole wall of the outer layer circuit board is controlled to be 20 to 25um.
As a further improvement of the present invention, in step S5, before performing surface treatment on the outer-layer circuit board, a selective oil is coated on the electrogilding region on the upper bottom surface of the outer-layer circuit board, and then the outer-layer circuit board is baked; after baking, performing other surface treatment on other areas of the non-electric gold area on the upper bottom surface of the outer layer circuit board; and removing the selected oil on the surface of the circuit board after performing other surface treatment on the non-electric gold area on the upper bottom surface of the outer layer circuit board.
As a further improvement of the invention, the outer layer circuit board is two or more layers of circuit boards.
Corresponding to the prior art, the manufacturing method effectively overcomes the defects of the traditional nickel and gold electroplating process of the circuit board, adopts film auxiliary design to be matched with a dry film, firstly manufactures the circuit on one surface of the circuit board by different characteristics of acid and alkali etching processes, exposes and hardens the copper surface on the other surface of the circuit board by the dry film for protection, then covers the dry film on the upper bottom surface and the lower bottom surface of the circuit board, exposes and hardens the areas, which do not need to be electroplated with nickel and gold, of the circuit board for protection, and exposes the areas, which need to be electroplated with nickel and gold, of the circuit board for nickel and gold electroplating treatment; after electrogilding, adhering dry films to the upper bottom surface and the lower bottom surface of the circuit board, then manufacturing a circuit on the other surface of the circuit board by using a film, and directly exposing and hardening the circuit on one surface of the manufactured circuit board by using the film to form a protective layer; then, subsequent processing is carried out; by adopting the mode, the defect that the original circuit board is reduced in copper and etched again to cause the thickness of original copper is effectively overcome, the thickness of copper of a thick copper circuit board cannot be reduced in the production process, the problem of suspended nickel and gold metal edges cannot be caused, the quality of the circuit board is improved, and the stability of signal transmission of the assembled circuit board and the performance of a product are ensured. In addition, the manufacturing method has the different characteristics of simple process flow, adoption of the auxiliary film and the dry film for matching use and acid-base etching. The operation is simple, the cost is more substantial than other processes, the production cost is effectively reduced, the practicability is strong, and the popularization and the use are convenient.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A thick copper circuit board without nickel and gold hanging edge comprises an outer layer circuit board; the upper bottom surface of the outer layer circuit board needs to be processed by electronickelling and electrogilding; the lower bottom surface of the outer layer circuit board does not need to be subjected to electro-nickel and electro-gold treatment; the manufacturing method of the outer layer circuit board comprises the following specific steps:
s1, drilling, removing glue residues, depositing copper in holes and electroplating the whole board on an outer layer circuit board;
firstly, according to the design circuit of the circuit board, drilling is carried out on the outer layer circuit board, a via hole is formed in the circuit board, and the circuit layer in the circuit board is conducted through the via hole. And then removing the glue residues left on the surface of the outer layer circuit board and in the through hole after the drilling of the outer layer circuit board, so that the surface of the circuit board and the through hole are clean. Performing in-hole copper deposition on the outer layer circuit board after the glue residues are removed to form a copper layer on the hole wall of the via hole of the outer layer circuit board, and conducting the circuit layers communicated with the via hole by utilizing the copper layer formed in the via hole by using a copper deposition process, so as to form a signal channel between the circuit board layers; when the circuit board is processed by the in-hole copper deposition process, the thickness of a copper layer formed after the whole board is electroplated after copper deposition in the hole of the outer layer circuit board is controlled to be 20 to 25um. Carrying out full-board electroplating on the outer-layer circuit board subjected to copper deposition in the hole, and forming a thickened copper layer on the surface of the outer-layer circuit board, so that the conductivity of the conductive layer of the outer-layer circuit board is increased; wherein, when the circuit board is processed by the full-board electroplating process, a copper layer with the thickness of more than 70um is electroplated on the surface of the circuit board. After the outer layer circuit board is processed by the in-hole copper deposition and full-board electroplating processes, a copper layer is electroplated on the surface of the outer layer circuit board and the hole wall of the via hole, and the thickness of the copper layer on the surface of the outer layer circuit board is more than 70 microns; the copper thickness of the hole wall of the via hole of the outer layer circuit board is controlled to be 20-25um.
S2, firstly, carrying out surface treatment on the outer layer circuit board, pasting a dry film, manufacturing a negative film isolation circuit film, aligning, exposing, developing, acid etching, film stripping and cleaning, and carrying out optical detection on the circuit on the upper bottom surface of the outer layer circuit board; the method comprises the following specific steps:
firstly, carrying out surface treatment on an outer-layer circuit board: removing impurities and an oxidation layer attached to the surface of the circuit board; then, adhering a layer of photosensitive dry film on the upper bottom surface and the lower bottom surface of the outer layer circuit board in a hot sticking mode;
manufacturing a film used for subsequent exposure; the film used in the process is a negative film circuit blocking film. Firstly, a first upper bottom surface negative film isolation circuit film corresponding to an upper bottom surface circuit diagram of an outer layer circuit board is manufactured by adopting a negative film isolation circuit film; a first windowing area is arranged on the first upper bottom negative film blocking line film; the first windowing area corresponds to an upper bottom line area of the outer layer circuit board and an area needing to be processed by an electro-nickel area and an electro-gold area; and manufacturing a first lower bottom surface negative film isolation circuit film corresponding to the lower bottom surface of the outer layer circuit board by adopting the full-page windowed negative film isolation circuit film. Because the negative film isolation circuit film is adopted to manufacture the circuit board circuit, during exposure, the dry film of the circuit board corresponding to the windowing region of the first upper bottom surface negative film isolation circuit film is hardened, so that the purpose of image transfer of the circuit board circuit is completed, and the dry film of the lower bottom surface of the exposed outer layer circuit board is completely hardened due to full-page windowing of the first lower bottom surface negative film isolation circuit film, so that the copper surface and the conductor of the lower bottom surface of the outer layer circuit board are protected, and the copper surface protection effect is realized.
The method comprises the steps that a first upper bottom negative film is adopted to block a circuit film to be aligned with an outer layer circuit board, after the first upper bottom negative film blocks the circuit film to be aligned with the outer layer circuit board, an upper bottom dry film of the outer layer circuit board is exposed, and as windowing processing is carried out on circuit areas on the first upper bottom negative film blocking the circuit film, positions in the exposed dry film on the upper bottom of the outer layer circuit board, which correspond to windowing areas corresponding to a first upper bottom negative film solder mask film, are hardened, so that the image of the first upper bottom negative film blocking the circuit film is transferred to the dry film on the upper bottom of the outer layer circuit board; and because the first lower bottom negative film blocking circuit film is windowed in the whole edition, when the lower bottom dry film of the outer layer circuit board is exposed by adopting the first lower bottom negative film blocking circuit film, the dry film of the lower bottom surface of the outer layer circuit board is completely hardened, so that the copper surface of the lower bottom surface of the outer layer circuit board cannot be etched in the subsequent circuit etching process, and the lower bottom copper surface of the outer layer circuit board is protected.
After the outer layer circuit board is exposed, developing is carried out; during development, the unexposed part of the dry film is melted and washed by using liquid medicine sodium bicarbonate, and the hardened dry film after exposure is left; then, circuit etching is carried out on the outer layer circuit board by using acid etching liquid, and because the circuit area of the upper bottom surface of the outer layer circuit board and the whole lower bottom surface of the outer layer circuit board are protected by the hardened dry film after exposure, only the copper surface exposed on the upper bottom surface of the outer layer circuit board is etched during acid etching, so that a circuit of the upper bottom surface of the outer layer circuit board is manufactured, and a conductor of an electric nickel area and an electric gold area is required to be processed;
after the circuit on the upper bottom surface of the outer layer circuit board and the area needing to be subjected to electronickelling and electrogilding are subjected to acid etching, an alkaline film stripping solution is adopted to strip the outer layer circuit board, and the dry film on the surface of the outer layer circuit board is dissolved by the alkaline film stripping solution to remove the dry film; and then cleaning the outer circuit board.
And (3) carrying out optical detection on the cleaned circuit board, detecting whether the circuit on the upper bottom surface of the outer layer circuit board meets the requirement, carrying out next production and processing if the circuit meets the requirement, and repairing or scrapping if the circuit does not meet the requirement. The optical detection adopts a developed automatic optical detection instrument, namely, the circuit of the circuit board can be detected.
S3, carrying out surface treatment, film pasting, positive film barrier circuit film manufacturing, alignment exposure, development, nickel and gold electroplating, film stripping and cleaning on the outer-layer circuit board; the method comprises the following specific steps:
firstly, carrying out surface treatment on an outer-layer circuit board to remove impurities and an oxidation layer attached to the surface of the circuit board; then sticking a layer of dry film on the upper bottom surface and the lower bottom surface of the outer layer circuit board in a hot sticking mode;
manufacturing a film used for subsequent exposure; the film used in the process is a negative film barrier film. First of all, the first step is to, manufacturing an upper bottom surface positive barrier film corresponding to the position of the area processed by the upper bottom surface electronickelling and electrogilding areas of the outer layer circuit board by adopting the positive barrier film; the positive barrier film on the upper bottom surface is provided with a positive barrier film windowing area; the positive film blocking film windowing area corresponds to an area, which needs to be processed by an electric nickel and electric gold area, on the upper bottom surface of the outer layer circuit board; and manufacturing a lower bottom surface positive barrier film corresponding to the lower bottom surface of the outer layer circuit board by adopting a full-page positive barrier film without opening a window. Because the position of the upper bottom surface positive film for blocking the film windowing area corresponds to the position of the area of the upper bottom surface of the outer layer circuit board which needs to be subjected to the electro-nickel and electro-gold area treatment, during exposure, the circuit board dry film corresponding to the area of the upper bottom surface positive film for blocking the film without windowing will be hardened, so that the dry film of the area of the upper bottom surface of the outer layer circuit board which needs to be subjected to the electro-nickel and electro-gold area treatment is removed during later processing, the dry films of other areas will be hardened, and a dry film protective layer is formed on the upper bottom surface of the outer layer circuit board; and the lower bottom positive barrier film is not windowed due to the whole plate, so that the dry film of the lower bottom of the outer layer circuit board is completely hardened after exposure, the copper surface of the lower bottom of the outer layer circuit board is protected, and the copper surface protection effect is achieved.
The method comprises the following steps of firstly aligning an upper bottom surface positive film blocking film with a circuit on the upper bottom surface of an outer layer circuit board, and then exposing an upper bottom surface dry film of the outer layer circuit board, wherein the position of a window opening area of the upper bottom surface positive film blocking film corresponds to the position of an area of the upper bottom surface of the outer layer circuit board, which needs to be processed by an electronickel area and an electrogilding area, so that the dry film of the area of the upper bottom surface of the outer layer circuit board, which needs to be processed by the electronickel area and the electrogilding area, is not hardened in the dry film on the upper bottom surface of the outer layer circuit board after exposure, and the dry films in other areas are hardened; and the lower bottom surface positive blocking film is windowed in a full page mode, so that when the lower bottom surface dry film of the outer layer circuit board is exposed by adopting the lower bottom surface positive blocking film, the dry film on the lower bottom surface of the outer layer circuit board is completely hardened, so that the copper surface of the lower bottom surface of the outer layer circuit board cannot be etched in the subsequent circuit etching process of the outer layer circuit board, and the copper surface of the lower bottom surface of the outer layer circuit board is protected.
After the outer layer circuit board is exposed, developing is carried out; during development, the unexposed part of the dry film is melted and washed by using liquid medicine sodium bicarbonate, and the hardened dry film after exposure is left; at the moment, the dry film of the area, which needs to be subjected to the electro-nickel and electro-gold area treatment, on the upper bottom surface of the outer layer circuit board is removed, and the hardened dry film covers the other part of the upper bottom surface and the lower bottom surface of the outer layer circuit board;
after development, removing the dry film of the area of the upper bottom surface of the outer circuit board which needs to be processed by the electronickelling and electrogilding areas, then processing the electronickelling and electrogilding on the outer circuit board, firstly plating a nickel layer in the electronickelling and electrogilding areas of the upper bottom surface of the outer circuit board, then processing the electrogilding on the outer circuit board, and plating a gold layer on the nickel layer of the upper bottom surface of the outer circuit board; therefore, the electro-nickel and electro-gold treatment is only carried out on the area, which needs to be subjected to the electro-nickel and electro-gold area treatment, on the upper bottom surface of the outer layer circuit board;
after the circuit on the upper bottom surface of the outer circuit board and the nickel and gold electroplating areas which need to be electroplated with nickel and gold, stripping the outer circuit board by using an alkaline stripping liquid, and dissolving the dry film on the surface of the outer circuit board by using the alkaline stripping liquid to remove the dry film; and then cleaning the outer circuit board.
S4, pasting a film on the outer layer circuit board, manufacturing a negative film barrier film, exposing, developing, acid etching, removing the film, cleaning and optically detecting the circuit on the lower bottom surface of the outer layer circuit board; the method comprises the following specific steps:
firstly, sticking a layer of dry film on the upper bottom surface and the lower bottom surface of the outer layer circuit board in a hot sticking mode;
manufacturing a film used for subsequent exposure; the film used in the process is a negative film barrier film. Firstly, a negative film blocking film is adopted to manufacture a second lower bottom surface negative film solder mask film corresponding to a lower bottom surface circuit diagram of the outer layer circuit board; a second windowing area is arranged on the second lower bottom surface negative resistance welding film; the second windowing area corresponds to the lower bottom surface circuit area of the outer layer circuit board; and manufacturing a second upper bottom surface negative film barrier film corresponding to the upper bottom surface of the outer layer circuit board by adopting the full-page windowed negative film barrier film. Because the negative film blocking film is adopted to manufacture the circuit board circuit, when the circuit board circuit is exposed, the dry film of the circuit board corresponding to the windowing region of the second lower bottom surface negative film blocking film can be hardened, so that the purpose of image transfer of the circuit board circuit is completed, and because the second upper bottom surface negative film blocking film is windowed in a full version, the dry film of the upper bottom surface of the exposed outer layer circuit board is completely hardened, so that the circuit of the upper bottom surface of the outer layer circuit board is protected, and the circuit protection effect of the upper bottom surface is achieved.
Aligning a second lower bottom negative film blocking film with the lower bottom surface of the outer layer circuit board, and then exposing a lower bottom dry film of the outer layer circuit board, wherein the circuit area on the second lower bottom negative film blocking film is subjected to windowing treatment, so that the exposed position of the windowing area corresponding to the second lower bottom negative film blocking film in the dry film of the lower bottom surface of the outer layer circuit board is hardened, and the image of the second lower bottom negative film blocking film is transferred to the dry film of the lower bottom surface of the outer layer circuit board; and the second upper bottom negative blocking film is opened by window opening, so when the lower bottom dry film of the outer layer circuit board is exposed by adopting the second upper bottom negative blocking film, the dry film on the upper bottom of the outer layer circuit board is etched on the circuit on the whole upper bottom, thereby protecting the circuit on the upper bottom of the outer layer circuit board.
After the outer layer circuit board is exposed, the dry film of the unexposed part is dissolved and washed by using liquid medicine sodium bicarbonate, and the hardened dry film after exposure is left; then, the circuit of the outer layer circuit board is etched by using an acid etching solution, and because the circuit area of the lower bottom surface of the outer layer circuit board and the whole upper bottom surface of the outer layer circuit board are protected by the hardened dry film after exposure, only the copper surface exposed out of the lower bottom surface of the outer layer circuit board is etched during acid etching, so that the circuit of the lower bottom surface of the outer layer circuit board is manufactured;
after the circuit on the lower bottom surface of the outer-layer circuit board is subjected to acid etching, stripping the outer-layer circuit board by adopting an alkaline stripping solution, dissolving a dry film on the surface of the outer-layer circuit board by using the alkaline stripping solution, and removing the dry film; and then cleaning the outer circuit board.
And carrying out optical detection on the cleaned circuit board, detecting whether the circuit on the lower bottom surface of the outer layer circuit board meets the requirement, carrying out next production and processing if the circuit meets the requirement, and carrying out repairing or scrapping treatment if the circuit does not meet the requirement. The optical detection adopts a developing automatic optical detection instrument, namely, the circuit of the circuit board is detected.
S5, carrying out solder mask oil silk-screen printing, word silk and other surface treatment on the outer layer circuit board;
after the circuits of the upper bottom surface and the lower bottom surface of the outer layer circuit board are manufactured, a layer of solder resist ink needs to be coated on the circuit board, and the solder resist ink is printed on the upper bottom surface and the lower bottom surface of the circuit board in a screen printing mode; then, putting the circuit board into an oven for low-temperature (73 ℃ 50 Min) pre-baking treatment, so that the solder resist ink on the surface of the circuit board is in a semi-cured state; then, exposing the circuit board by using a film to realize the pattern transfer of the film, and dissolving and washing unexposed parts of the solder resist ink by using liquid medicine; after washing, carrying out UV curing on the solder resist ink on the surface of the circuit board so as to further harden the solder resist ink on the surface of the circuit board; after the solder resist ink on the surface of the circuit board is hardened, character printing is carried out, and symbols and descriptions of components are printed in the designated area of the surface of the circuit board according to the requirements of customers; and (3) carrying out high-temperature final baking on the circuit board after the characters are printed, and drying and hardening the solder resist ink and the character ink on the surface of the circuit board to ensure that the hardness of the solder resist ink on the surface of the circuit board is more than 5H when tested by a pencil.
Before carrying out other surface treatment on the outer layer circuit board, coating selective oil on an electro-gold area on the upper bottom surface of the outer layer circuit board, and then baking the outer layer circuit board; after baking, performing other surface treatment (such as gold immersion or tin spraying) on the non-electric gold area on the upper bottom surface of the outer layer circuit board; and removing the selected oil on the surface of the circuit board after carrying out other surface treatment on the non-electric gold area on the upper bottom surface of the circuit board.
The surface treatment can be other surface treatment processes such as gold immersion, tin spraying and the like. The surface treatment process can be realized by adopting the existing surface treatment process.
And S6, forming and processing the outer-layer circuit board, and testing the electrical property function to obtain the circuit board.
After the surface of the circuit board is treated, the circuit board is molded, and the shapes of the circuit board, such as routing, bevel edge manufacturing and the like are processed according to the outline shape and size required by a customer during shape processing, so that the produced circuit board meets the requirements of the customer, and the circuit board is manufactured. And (5) after the circuit board is manufactured, carrying out quality detection, and delivering the circuit board to a customer after the circuit board is confirmed to be correct.
In this embodiment, after the outer-layer circuit board is processed by the in-hole copper deposition and full-board electroplating processes, a copper layer is electroplated on both the surface of the outer-layer circuit board and the hole wall of the via hole, and the thickness of the copper layer on the surface of the outer-layer circuit board can be more than 70um besides 70um as exemplified in this embodiment; the thickness of copper of the hole wall of the through hole of the outer layer circuit board is 20um, and the thickness of copper of the hole wall of the through hole of the outer layer circuit board can be any thickness value from 20 to 25um.
The outer layer circuit board can be a double-layer circuit board or an outer layer board of a multi-layer circuit board, wherein the copper thickness of the surface of the circuit board is 70um or more than 70 um; the board surface of the circuit board can be subjected to electronickelling and electrogilding by adopting the manufacturing method.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. A thick copper circuit board without nickel and gold hanging edges comprises an outer circuit board which needs to carry out circuit manufacturing on the upper bottom surface and the lower bottom surface of the circuit board; the upper bottom surface of the outer layer circuit board needs to be processed by electronickelling and electrogilding; the lower bottom surface of the outer layer circuit board does not need to be processed by electronickelling and electrogilding; the manufacturing method of the outer layer circuit board is characterized by comprising the following steps: firstly, the circuit on the upper bottom surface of the outer layer circuit board is manufactured, then the electric nickel and electric gold processing treatment is carried out on the electric nickel and electric gold area on the upper bottom surface of the outer layer circuit board, and then the circuit on the lower bottom surface of the outer layer circuit board is manufactured.
2. The method for manufacturing the thick copper circuit board without the suspended edge of the electric nickel and the electric gold according to claim 1, wherein the method for manufacturing the thick copper circuit board comprises the following specific steps:
s1, drilling, removing glue residues, depositing copper in holes and electroplating the whole board on an outer layer circuit board;
s2, firstly, carrying out surface treatment on the outer layer circuit board, pasting a dry film, manufacturing a negative film isolation circuit film, aligning, exposing, developing, acid etching, film stripping and cleaning, and carrying out optical detection on the circuit on the upper bottom surface of the outer layer circuit board;
s3, carrying out surface treatment, film pasting, positive film barrier circuit film manufacturing, alignment, exposure, development, electronickelling, electrogilding, film stripping and cleaning on the outer-layer circuit board;
s4, pasting a film on the outer layer circuit board, manufacturing a negative film for blocking a circuit film, aligning, exposing, developing, acid etching, removing the film, cleaning and optically detecting the circuit on the lower bottom surface of the outer layer circuit board;
s5, carrying out solder mask oil silk-screen printing, character printing and other surface treatment of non-electric gold positions on the outer layer circuit board;
and S6, forming and processing the outer-layer circuit board, and testing the electrical property function to obtain the circuit board.
3. The method for manufacturing the thick copper circuit board without the suspended edge of the electric nickel and the electric gold according to claim 2, wherein the step S2 comprises the following steps:
s21, firstly, carrying out surface treatment on the outer-layer circuit board, and then pasting a layer of dry film on the upper bottom surface and the lower bottom surface of the outer-layer circuit board;
s22, manufacturing a first upper bottom surface negative film isolation circuit film corresponding to an upper bottom surface circuit pattern of the outer layer circuit board by adopting the negative film isolation circuit film; a first windowing area is arranged on the first upper bottom negative film blocking line film; the position of the first windowing area corresponds to the positions of an upper bottom surface circuit area of the outer layer circuit board and an area needing to be subjected to electro-nickel and electro-gold area treatment; manufacturing a first lower bottom surface negative film isolation circuit film corresponding to the lower bottom surface of the outer layer circuit board by adopting a full-page windowed negative film isolation circuit film;
s23, aligning and exposing the upper bottom surface dry film of the outer layer circuit board by adopting a first upper bottom surface negative film blocking circuit film, and aligning and exposing the lower bottom surface dry film of the outer layer circuit board by adopting a first lower bottom surface negative film blocking circuit film; then carrying out development and acid etching to manufacture a circuit on the upper bottom surface of the outer layer circuit board and an area needing electronickness and electrogilding;
s24, removing the film of the outer-layer circuit board by using an alkaline film removing liquid, and then cleaning the outer-layer circuit board;
and S25, carrying out optical detection on the circuit on the upper bottom surface of the outer layer circuit board.
4. The method for manufacturing the thick copper circuit board without the suspended edge of the electric nickel and the electric gold according to claim 3, wherein the step S3 comprises the following steps:
s31, firstly, carrying out surface treatment on the outer layer circuit board, and then pasting a layer of dry film on the upper bottom surface and the lower bottom surface of the outer layer circuit board;
s32, manufacturing an upper bottom surface positive barrier circuit film corresponding to the upper bottom surface of the outer layer circuit board by adopting the positive barrier circuit film; the film of the upper bottom surface positive barrier circuit is provided with a positive barrier circuit film windowing area; the position of the positive film blocking circuit film windowing area corresponds to the position of an area, needing to be processed by the nickel and gold areas, on the upper bottom surface of the outer layer circuit board; adopting a full-page windowed positive solder resist film to manufacture a lower bottom surface positive barrier circuit film corresponding to the lower bottom surface of the outer layer circuit board;
s33, firstly, exposing the upper bottom surface dry film of the outer layer circuit board by adopting an upper bottom surface positive film to block the circuit film, and then exposing the lower bottom surface dry film of the outer layer circuit board by adopting a lower bottom surface positive film to block the circuit film; then carrying out development;
s34, after development, performing electric nickel and electric gold treatment on the outer-layer circuit board, electroplating a nickel layer in an electric nickel and electric gold area on the upper bottom surface of the outer-layer circuit board, then performing electric gold treatment on the outer-layer circuit board, and electroplating a gold layer on the nickel layer on the upper bottom surface of the outer-layer circuit board;
s35, removing the film of the outer-layer circuit board by using an alkaline film removing liquid, and then cleaning the outer-layer circuit board.
5. The method for manufacturing the thick-copper circuit board without the suspended edge for the electronickelling and the electrogilding as claimed in claim 4, wherein the specific steps of the step S4 are as follows:
s41, attaching a layer of dry film to the upper bottom surface and the lower bottom surface of the outer layer circuit board;
s42, manufacturing a second lower bottom surface negative film isolation circuit film corresponding to the lower bottom surface circuit diagram of the outer layer circuit board by adopting the negative film isolation circuit film; a second windowing area is arranged on the second lower bottom negative film blocking circuit film; the second lower windowing region corresponds to the lower bottom surface circuit region of the outer layer circuit board; a second upper bottom surface negative resistance welding film corresponding to the upper bottom surface of the outer layer circuit board is manufactured by adopting a full-page windowed negative resistance welding film;
s43, exposing the lower bottom surface dry film of the outer layer circuit board by adopting a second lower bottom surface negative film blocking circuit film, and then exposing the outer layer upper bottom surface dry film by adopting a second upper bottom surface negative film blocking circuit film; then carrying out development and acid etching to manufacture a circuit on the lower bottom surface of the outer layer circuit board;
s244, removing the outer layer circuit board by using an alkaline film removing liquid, and then cleaning the outer layer circuit board;
s45, carrying out optical detection on the circuit on the lower bottom surface of the outer-layer circuit board.
6. The method for manufacturing the thick-copper circuit board without the suspended edge of the electronickelling and the electrogilding as claimed in any one of claims 2 to 5, is characterized in that in the step S1, after the outer circuit board is processed by copper deposition in the hole and full-board electroplating, a copper layer is electroplated on the surface and the hole wall of the outer circuit board, and the thickness of the copper layer on the surface of the outer circuit board is more than 70 microns; the copper thickness of the hole wall of the outer layer circuit board is controlled to be 20 to 25um.
7. The method for manufacturing thick copper circuit board without suspended edge of electronickelling and electronickelling according to claim 6, wherein in step S5, before surface treatment of the outer circuit board, the electickelling area on the upper bottom surface of the outer circuit board is coated with selected oil, and then the outer circuit board is baked; after baking, performing other surface treatment on other areas of the non-electric gold area on the upper bottom surface of the outer layer circuit board; and removing the selected oil on the surface of the circuit board after performing other surface treatment on the non-electric gold area on the upper bottom surface of the outer layer circuit board.
8. The method for manufacturing the thick copper circuit board without the suspending edge of the electric nickel and the electric gold according to claim 7, wherein the method comprises the following steps: the outer layer circuit board is two or more layers of circuit boards.
CN202210918965.3A 2022-08-02 2022-08-02 Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding Pending CN115397116A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210918965.3A CN115397116A (en) 2022-08-02 2022-08-02 Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210918965.3A CN115397116A (en) 2022-08-02 2022-08-02 Method for manufacturing thick copper circuit board without suspended edge for electronickelling and electrogilding

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CN115397116A true CN115397116A (en) 2022-11-25

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